He's Not A Spare Son

Dustin Curran was born the true heir of the Curran family, but a fortune teller's scheme put another boy in his place, and Dustin was sent to the countryside to live with his grandfather. His grandfather died when he was eight and his parents took him back. His adopted brother framed him soon after, and his parents disowned him and left him at the Clearwind Sect. He stayed and trained there for years, rising to the rank the sect calls the earthly immortal. His parents turned up again once he had reached it, asking him to come down and marry Linda Collins, who had married into her family as an outsider and was not expected to live long. Dustin asked them what their regret was worth now, since they had been the ones begging him to leave.